Field of the Invention
The invention relates to an optical device, and particularly relates to a projector.
Description of Related Art
A projector is a display device used to produce images. A projector is to convert an illumination beam produced by a light source into an image beam by using a light valve, and then project the image beam onto a screen or a wall through a projection lens to form an image.
Generally, a projector has a light source module for providing the light necessary for the projected image. FIG. 6 is a schematic diagram of a conventional projector 600. The projector 600 includes a light source module 610 and an optical engine 620, wherein the light source module 610 includes a plurality of light sources 612, a combiner 614 and a collimator lens 616, and the optical engine 620 includes a phosphor wheel 622 and a plurality of relay lenses 624. The light sources 612, for example, use a plurality of blue light laser diodes, and the blue light emitted by the plurality of blue light laser diodes are concentrated and transmitted to the collimator lens 616 through the combiner 614, then the blue light is transmitted to the phosphor wheel 622 through the relay lens 624 or other type of optical component, such that a portion of the blue light is converted into red light and green light by the phosphor wheel 622. To increase the brightness of the projected image, typically the number of laser diodes will be increased in the projector design. However, with the increase in the number of laser diodes, the size of the combiner 614 increases correspondingly, for effectively concentrating the blue light emitted by the laser diodes. This may increase the manufacturing cost of the light source module 610. Additionally, with the increase in size of the combiner 614, light beams emitted by a portion of the laser diodes need a larger bending angle for transmission toward the collimator lens 616 after passing through the combiner 614, therefore the difficulty in design of the light source module 610 is greatly increased.
Taiwan patent number TWM337114 discloses an illumination system, where the light emitted by the light source of the illumination system sequentially passes through the integration rod and the focus unit to arrive at the color wheel. China patent number CN101063519 discloses an illumination system, where the illumination system utilizes optical fibers for guiding the light emitted from the light source. United States patent publication number US20090168025 discloses an illumination system, where the light emitted by the light source of the illumination system passes through optical fibers to arrive at the integrator. Taiwan patent number TW439993 discloses integration rods which can be hollow integration rods or solid integration rods.
The information disclosed in this “BACKGROUND OF THE INVENTION” section is only for enhancement understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Furthermore, the information disclosed in this “BACKGROUND OF THE INVENTION” section does not mean that one or more problems to be solved by one or more embodiments of the invention was acknowledged by a person of ordinary skill in the art.